Tight end Saubert made the game-winning two-point conversion for Seattle.
Seattle staged a stunning comeback to overcome the Rams in overtime, clinching their spot in the NFL play-offs.
Rallying from a 30-14 deficit in the final period, the Seahawks triumphed by a single point at home, notching their fifth consecutive victory.
While the Los Angeles had already secured a playoff spot earlier on Sunday, the Seahawks booked their return to the play-offs after a 24-month absence.
With this outcome, the Seattle have taken over their Conference race with a twelve and three record, replacing the Rams, who fell to the fifth playoff position with an eleven and four record.
Signal-caller Sam Darnold threw two interceptions but recovered to make two touchdown passes, including the second TD to star receiver Jaxon Smith-Njigba in the extra period.
The visitors held a 13-7 lead at the break before Walker broke free for a 55-yard scoring dash for the home side.
Los Angeles defensive back Josh Wallace then returned Darnold's first pick for 56 yards, setting up a one-yard score by Corum on the ensuing snap.
In the final stanza, a scoring pass from Matthew Stafford to Puka Nacua extended the advantage to sixteen points, but Rashid Shaheed ignited Seattle's hope with a spectacular return for a score.
Darnold then connected with Barner in the endzone, and a successful conversion forced the contest into overtime.
Although Puka Nacua scored for his another touchdown in overtime, Smith-Njigba answered in kind to set up the decisive conversion.